Already in 1993, criteria for the selection of radionuclides for immunotherapy with α-emitters and β-emitters were provided for the first time by GEERLINGS (GEERLINGS, M. W. (1993): Int. J. Biol. Markers, 8, 180-186: “Radionuclides for radioimmunotherapy: criteria for selection”) where it turned out due to the difference in energy that the amount of α-emitters to be applied may be more than 1000 times lower than that of β-emitters, if a comparable effect is to be achieved.
Moreover, in the work of GEERLINGS 1993 the α-emitting radionuclides 225Ac and its daughter isotope 213Bi turned out to be highly promising for the objects of radioimmunotherapy alongside the in principle usable, however relatively poorly available or instable antibody conjugate producing α-emitters: 211 At, 255 Fm, 212Bi/212Pb, 224Ra, 233Ra.